/Engine/Plugins/Experimental/UserToolBoxCore/Source/UserToolBoxCore/Public/UserToolBoxSubsystem.h
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)(BlueprintType) class UUserToolboxSubsystem : public [UEditorSubsystem](API\Editor\EditorSubsystem\UEditorSubsystem)
FOnTabChanged
OnTabChanged